An acclaimed symphony conductor was booted from her day job at a Manhattan high school yesterday for allegedly making her students play second fiddle to her orchestra.

Dorrit Matson's respected career hit a sour note when city school investigators charged she had robbed taxpayers and cheated students by repeatedly calling in sick - to perform at lower Manhattan's famed Trinity Church.

"She should be required to repay the [city] for any salary to which she was not entitled," Special Schools Investigator Richard Condon wrote in a letter to Schools Chancellor Joel Klein.

But Matson's doctor told investigators she had called in sick from the High School for Humanities in Chelsea because she suffers from chronic fatigue syndrome - brought on by the school's administrators.

The doctor, who was not named, claimed that conducting the 46-piece New York Scandia Symphony was acceptable for the music teacher because it did not add to her stress, officials said yesterday. Condon, however, turned a deaf ear to the doctor's excuses and recommended that the Denmark-born conductor be fired from her $64,000-a-year job teaching city kids.

Matson, who founded the New York Scandia Symphony in 1988, allegedly called her school's principal last Nov. 16 and claimed she was sick and would not be able to teach for most of the week, authorities said. But two days later, she conducted a performance that was broadcast on public radio, authorities said.

In February, Matson, who has been praised as one of the finest female conductors in the nation, requested a leave of absence without pay, saying she suffered from chronic fatigue syndrome.

She then conducted performances on Feb. 17 and May 12, officials said.

Curious investigators compared her sick days with her performance schedule going back several years and found Matson had called in sick to conduct the symphony several times, officials said.

Matson, who has taught in city schools since 1988, could not be reached yesterday. But Klein's chief counsel Michael Best said: "This abuse of sick leave is completely unacceptable, and we will seek her termination."

She is the second teacher this summer to infuriate authorities for allegedly abusing sick time.

In June, investigators laid the smackdown on a Queens high school teacher Matt Striker who allegedly called in sick while he donned tights for World Wrestling Entertainment.

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